How to pressure test a cornie keg

Hey just thought I would share some info on how to pressure test kegs without buying any additional equipment. I learned this trick from a soda distributor who has been selling used kegs.

Apparently the easiest way to pressure test a keg is to pup it up to 20psi so that it seals and flip the lid hatch so that the only thing keeping the lid on is the internal pressure inside the keg. Then you just simply let the keg sit for 3 days to a week. If the lid falls in on its own or if it falls in when you tap it lightly there is a small leak. At 20 psi you should have to press down on the lid with a fair amount of pressure to get it to cave in.

Simple and requires no additional equipment.

makes sense.. gonna try on a few kegs tonight..

thanks

I see some problems with this method

1 you are wasting CO2 unless you don't have leak and you recapture the CO2 or use compressed air

2 a little bit of soapy water or Star-San solution and a sponge or trigger sprayer isn't my idea of buying special or additional equipment

3 it's much easier and faster just to spray some soapy water or Star-san solution on and around the lid and posts and look for bubbles rather than wait a day or so to see if you've lost pressure

4 I have had cornies that held pressure at 20 PSI but leaked at serving pressure of 5-8 PSI so while this test may be valid for 20 PSI you still don't know how your cornie will perform at serving pressure

But if you have unlimited access to free CO2 and plenty of time to do tests that last days at various pressure levels then, no problem

abracadabra said:

I see some problems with this method

1 for the most part you are wasting CO2 unless you don't have leak and recapture the CO2 in the cornie or use compressed air

2 a little bit of soapy water or Star-San solution and a sponge or trigger sprayer isn't my idea of buying special or additional equipment

3 I have had cornies that held pressure at 20 PSI but leaked at serving pressure of 5-8 PSI so while this test may be valid for 20 PSI you still don't know how your cornie will preform at serving pressure

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1. CO2 is cheap, I get my 20lb tank filled for $12 - the biggest hassle is dragging the thing over to airgas and exchanging it.

2. This method isn't to detect a visible leak, as with soap and water but rather a slow leak that can still drain your tank.

3. The guy said 20 psi which is probably soda pressure, I am sure you can give it a shot at serving pressure (mine is between 8 - 12 psi) and see if it works.

So am I just retarded or would it still work if you filled it 3/4 with water to save some co2? I'm assuming that would work unless the compressed gas has to have access to the bottom of the dip tube. Just thinking out loud.

silvervan83 said:

So am I just retarded or would it still work if you filled it 3/4 with water to save some co2? I'm assuming that would work unless the compressed gas has to have access to the bottom of the dip tube. Just thinking out loud.

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This is what I do...then spray the top with a soapy water mix. No need to wait, you'll be able to see right away if it's leaking, and where it's leaking from.

I just put a little Star San in them after cleaning, seal them up and hit them with some compressed air...

I can see if your a reseller and your getting hundreds of kegs at a time a CO2 was free.

But there's no way I'm waiting a week to see if a keg has a keg a 20psi..

costs me $40 to get my 20lbs tank filled and it takes a week (so they say)

I Haven't actually tested any cornies yet but I'm getting 16 on Sunday. I've already bought new O-ring kits for 6, I plan on cleaning, replacing the O-rings and doing like suggested above and filling 3/4 with water. I'll seal the lid with 20 or more PSI for a bit then drop it down to serving pressure and use soap and water in a spray bottle to check for leaks.

Like I said if I was doing several hundred kegs at a time I'd probably go with the pressurize and forget method aswell..

Cornies are meant for up to 130 PSI, and it takes 20-30 PSI to get a good seal on the lid seal.. Just throwing that out there...

I clean and sanitize my corny kegs, then hit them with 25-40 PSI to seat all the seals. If they're not still holding significant pressure on racking day, I pick a different keg to rack into, then rebuild.

However, my turnover is slow enough that a clean corny might sit around for a couple of months before I want to rack into it.

jds said:

I clean and sanitize my corny kegs, then hit them with 25-40 PSI to seat all the seals. If they're not still holding significant pressure on racking day, I pick a different keg to rack into, then rebuild.

However, my turnover is slow enough that a clean corny might sit around for a couple of months before I want to rack into it.

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Exactly. The average brewer should be able to just pressurize clean kegs and test them when your kegging. Try to remember which way the lid is on when you take it off. It does have an affect on the seal.

im picking up 50 corny and selling them, my buyer is requesting that the kegs be pressured up when he gets them, my supplier said the kegs work and guarantees them to be in working order, but is not going pressure them up for me.

would a 5# CO2 tank have enough juice to test all 50 kegs? I don't have a problem about "wasting" CO2 as its only $6 to get my tank filled. my problem is I am not going to have my CO2 tank and kegging equipment in time before I make this business deal.

would I be able to use an air compressor to pressurize the kegs?

-=Jason=-

Edits in red.

For your first question, let's say you want to pressurize to 1atm (14.7 PSI) gage pressure. That's 2atm total pressure. No, it isn't. It's 1 atm of pressure to be added

At STP, you need 5 gallons * 3785 cc/gal * 2 = 37850 cc's of gas per keg. You'll actually need a touch more, because a corny contains a bit over 5 gallons including headspace. Nope. Take the factor of two out for the reason I stated above. you need a bit over 18925 CC's.

The density of CO2 at STP is 0.001977 g/cc . that works out to 75 Nope, 37-1/2 grams of CO2 for an exact 5 gallons.

5 lb * 454 g/lb * 1 keg / 75 (37)grams is just over 30 (60)kegs. So, no, one 5 lb bottle won't pressurize all your kegs. You'll need two, and that might be pushing it. Actually, one bottle can theoretically handle somewhere under 60 kegs to 14.7 PSI. It's close

I don't see why you can't pressurize with air. The only hiccup I can see is if your compressor provides lubricated air. If it does, buyers might not appreciate the film of oil on the inside of the keg. That said, if the kegs still hold old syrup, I doubt anyone would ever notice.

thanks, jds.

I don't have a compressor but the neighbor does I was going to ask to borrow it, but I'd rather not borrow anything and just pay $12 worth of Co2. thats what I'll probably do maybe I'll ask the neighbor if I can use his bottle of Co2 and I'll return it filled up.

since I'll have the kegs before my kegging kit arrives. damn Perlick 525SS faucets holding up my order.

-=Jason=-

Now that I consider this a bit more, you only need half as much gas as I said, since the kegs are (presumably) at 1 ATM when you start filling them. One 5 lb bottle might get you there if you fill to 15 PSI, but it'll be close. You'll want a second one on hand just in case.

welding supply is only 5 minutes from my house, if I run out I'll just take the bottle down and get it filled again.

I guess I see where my buyer is coming from he doesn't want to re-sell cornys in his shop that are leaking, but my supplier told me if any are defective just let them know and they will trade them out no problem.


-=Jason=-

Do people really have a big problem with leaking kegs? I might have had 1 or 2 in ten years, but mostly they've been no problem. I often keep them pressurized when I store em empty, but if I clean one out to fill it I never check until it's connected to gas then a little Starsan doe the trick.

Sea said:

Do people really have a big problem with leaking kegs? I might have had 1 or 2 in ten years, but mostly they've been no problem. I often keep them pressurized when I store em empty, but if I clean one out to fill it I never check until it's connected to gas then a little Starsan doe the trick.

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well for me im selling 50 kegs and my buyer won't buy unless they are pressurized hence why I need them to be when i deliver. thats a lot of money I can't pass up on this deal.

-=Jason=-